From German Pat. No. 646,308 a kneading and mixing machine of the above-mentioned kind is known in which the blades extend along the whole bladed member and have the same inclination and are rectangular in cross-section. This known kneading machine has the disadvantage that it has only a poor drawing-in action on the material to be kneaded or mixed, a poor discharge action and an inefficient mixing action.
The invention sets out to overcome the problem of providing a kneading and mixing machine of the above-mentioned kind, in which the material to be kneaded at the commencement of the kneading process is efficiently drawn-in, and at the end of the kneading process is efficiently discharged, and, during the kneading action is thoroughly mixed.
This problem is solved in accordance with the ivention in that each bladed member of at least two adjacent members, has a blade section of opposite hand and the blades have a triangle-like section, the base of the triangle faces the shaft, the apex lies opposite the base and forms a cam and that the sides of the triangle adjacent the base join at the opposed face.
By the combination of the oppositely handed blade sections and the triangle-like blades the kneading material is rapidly drawn in by the blade members and is thoroughly mixed. In spite of the high mixing power of the kneading and mixing machine in accordance with the invention the kneaded material is not excessively heated during the mixing process. The kneading machine discharges the kneaded material equally as efficiently as it is drawn in. Because of the opposite-handed nature of the blade sections at the connecting plane thereof the kneaded material is moved forward as a result of which a particularly intimate mixing is produced. Since the one bladed member with its cam surfaces progressively passes the opposing surfaces of the other bladed member, because of the different peripheral speeds of the surfaces passing one another an additional shearing effect is produced which improves the mixing action. The mixed material is subjected during the mixing process to a high pressure and is forced to pass along the blades in thin layers.
In a preferred embodiment of the invention, it is provided that the blades of the two blade sections at the connecting plane are out of phase in relation to one another. By the phase shift of the blades at this plane the mixed material is taken alternately by the one and the other blade section. By the continual displacement to and fro of the mixed material it is particularly intimately mixed.
A further advantageous embodiment of the invention is provided when the different blade lengths are provided, the longer blades of the blade section projecting into the opposite faces of the other blade section so that a dispersed or scattered connecting surface is produced. The mixing power is still further increased as a result.